Device for reclaiming dry powder particulates

ABSTRACT

A moveable backdrop filter element mounted for travel over a plurality of rollers and arranged for collecting and reclaiming surplus dry powder particulates, such as used in electrostatic deposition systems. A particular feature of the invention is the ready interchangeability of the filter elements to permit the rapid change of deposition colors.

United States Patent 1 Hardy 11 3,744,450 51 July 10,1973

1 1 DEVICE FOR RECLAIMING DRY POWDER PARTICULATES [76] lnventor: SheilaHardy, 400 North Avenue,

Bartlett, 111. 60103 [22] Filed: Nov. 19, 1971 [21] Appl. No.: 200,451

[52] U.S. C1 118/326, 98/115, 118/309, 118/634 [51] Int. Cl B05b 1/28,BOSb 15/04 [58] Field of Search l18/DIG. 7, 309, 118/326, 634, 639, 640;117/9341, 102 A; 98/115 SB [56] I References Cited UNITED STATES PATENTS3,201,272 8/1965 Forshee 117/102 2,752,003 6/1956 Hersey, Jr. et a1183/61 2,217,247 10/1940 Burns 91/44 3,537,424 11/1970 Sadler 118/63,395,972 8/1968 Hardison 23/4 2,730,460 l/l956 Ransburg 117/93 FOREIGNPATENTS OR APPLICATIONS 3,194 9/1910 Great Britain 118/326 X PrimaryExaminer-Mervin Stein Assistant ExaminerLeo Millstein Attorney-Edward M.Apple [5 7 ABSTRACT A moveable backdrop filter element mounted fortravel over a plurality of rollers and arranged for collecting andreclaiming surplus dry powder particulates, such as used inelectrostatic deposition systems. A particular feature of the inventionis the ready interchangeability of the filter elements to permit therapid change of deposition colors.

5 Claims, 3 Drawing Figures PATENTEBJUHO'W 3,744,450

h Am H111mmg Fi 1 g 3 33 13 1 5A 13A 25A 24 17 30 3 INVENTOR: 20A 7 LSheila Hardy BY: 11 (M 2 ATTORNEY DEVICE FOR RECLAIMING DRY POWDERPARTICULATES This invention relates to electrostatic deposition systems,in which dry powder particulates are deposited on work pieces, prior tothe heat treating operation.

This invention is an improvement on the invention disclosed in US.letters Pat. No. 3,201,272 issued to me Aug. 17 1965 under my previousname Sheila Forshee. In that Patent 1 disclosed a METHOD AND MEANS FORTRAPPING AND RECLAIMING POR- CELAIN FRIT. That disclosure concerneditself with the handling of wet substances, whereas the instantdisclosure relates to the trapping and reclamation of the over spray ofdry powder. used in electrostatic deposition operations.

In the electrostatic deposition and reclamation and other systems, nowknown to the public, various pieces of equipment are necessitated, forexample, in addition to the conventional electrostatic gun and supplyelements a cyclone power unit, complicated conduits and bag stations areused and-when the production schedule calls for achange in color, theentire set-up has to be changed, all of which is time consuming andeconomically unsound, because ofdown-time in production and cost oflabor in the change over.

It is therefore an object of this invention to obviate the foregoingdifficulties and to produce other beneficial results.

Another object of the invention is to provide a trapping and reclamationsystem for dry powder particulates,which is compact in size, inexpensiveto assemble and operate, and efficient in use.

' Another object of the invention is to provide a dry powder reclamationsystem,'which is constructed and arranged so that change of colors inthe particulates used may be effected rapidly and deconomically.

I Anotherobject of the invention is to provide a mechanism of thecharacter indicated indicated inlwhich the filter media may be changedrapidly by the simple expeident of removal and replacement, through cutout portions of the spray booth housing.

Another object of the invention is to provide an endless b'elt typefiltering media, which is carried on rollers, at least one of which istension adjustable, from the exterior of the device.

Another object of the invention is to provide an endless belt type offiltering media which may be removed,

replaced, and adjusted by removing one or moresimple cover plates fromthe housing.

Another object of the invention is to provide a mechanism of thecharacter indicated which performs double filtering actions, whereby torender negative emis-- sion-to-atmosphere of particulates, which mightbe damaging to the ecology. I Another object of the invention is toprovide a powder deposition and reclamation system which can readily beused in continuing, or constant indexing, powder coating operations ofheavy production.

Another object of the invention is to provide a device of the characterindicated in which the filter media for the dry powerder partciualtesmay be felt, paper, or any other material which will allow the passagethere through of air, but will trap even the finest of particulates toreach the media.

Another object of the invention is to provide a device ofthe characterindicated which has a high safety factor in that the collected over shotpowder is quickly removed from the spraying area.

Another object of the invention is to provide a device of the characterindicated in which'the dry particulates recovered are made more easilyaccessible for rc-use.

Another object of the invention is to provide means to protect themediasupport shafts from any powder particulates, which might reach thearea between the front and return portions of the endless belt filter.

Another object of the invention is to proivde a mechanism arranged sothat air going through the return portion of the endless belt removesany residue of powder, not removed by the brushes, scraper, .orvibrator.

The foregoing and other objects-and advantages of the invention willbecome more apparent as the description proceeds, reference being madefrom time to time to the accompanying drawing, forming part of thewithin disclosure, in which drawing:

FIG. 1, is a side elevational view ofa device embody-' on the lineclosed the reference character 5, indicates a work' piece,which is beingsprayed with a coating from a conventional electrostatic gun. Thereference character 7, indicates in general, the spray booth which inthis instanceconsists of a comparatively heavy side wall 8, a top wall9, a back wall 10, an air plenum 10A, and a source of air supply notshown, and a comparatively light weight side wall 11, the major portion11A, of which is supported, as at 13, and 1 3A at one end of a bridgelike, cantilever, assembly 14, comprising elements 14A, 14B, 14C, and14D, which assembly is welded, or otherwise secured, as at 15, and 15A,to the heavy side wall 8. The side wall 8 also carries heavy bearings16, 17, and 18, which support at one end the rollers 19, and 20, and theshaft of a rotable brush 21 which is used to remove the overspray fromthe media 25, and cause it to fall into a removalb'e receptacle 258. Thebrush 21 is rotated by a motor 21A, and belt 218. The rollers 22, and 23(FIG. 1) are likewise supported at one end by bearings (not shown)carried by the side wall 8. It will be understood that these bearingsare large enough, and have thrust capabilities to hold the rollers atone end only, when the bearings at the opposite ends of the rollers aretemporarily removed, as hereinafter described. The side wall ll1lA has acut out portion 24 (FIG. 2) which is substantially of ,the contour ofthe endless belt filter media 25, which passes over the rollers as shownin FIG. 1. The spaces between the edges of the media belt 25, and theside walls 8-11 are sealed as at25ArThe cut out 24 is trapezoidal incontour and is defined between the adjacent edges of the portions 11,and 11A of the side wall 11, and is of sufficient width to permit theentry of a mans hands, or any tool, which may be used to'instalL'orremove, the filter media 25, endwise from the rollers. This is animportant feature of theinvention as it permits the filters 25 to beremoved and replaced from the side of the spray booth, when a change ofcolor is indicated. The filter media may be the material as disclosed inUS. Pat. Nos. 2,841,073, 2,875,680, 3,071,060, 3,201,272 issued to meunder my previous name,

Sheila Forshee, or it may be cloth, paper, felt or any other materialfound efficient for use in catching fine, dry powder particulates.

Although I have here in disclosed the use of an endless belt type offilter media, it will be understood that I may also use a media whichhas ends, and the ends may be joined together by any suitable means toform an endless belt. With such a structure the media could also bepositioned over the rollers from the front.

[twill also be understood that I intend to seal the spray booth betweenthe edges of the media 25, and the side walls 8-11 of the of the boothby any suitable means available.

The media 25 is reinforced against air movement in the direction of thearrows, as at 26 and 27 as in conventional practice. The cut out 24 iscovered by removable cover plates 28, 29, and 30 which are secured inplace by machine screws 31 (FIG. 1) which engage .30 and the same end ofthe shaft, of the brush 21 is carried by the side wall 11.

The roller 20 is an idler, as are the rollers 22 and 23.

- g The roller 19 is driven, as at 32, by a belt and motor 33.

The idler 20 is mounted in bearings (not shown) carried by blocks whichare adjustable in slides 34, carried on the inside of both the walls 8and 11A. The blocks are adjusted by threaded rods 35. The rods 35 areaccessible through the cut out 24, and a covered cut out (not shown) inthe sidewall 8. By adjusting the rods 35, the roller 20 may be moved toand away from the filter media 25. Movement of the roller 20 away fromthe return section of the filter media 25, developes slack in theendless belt 25, so that it can more easily be removed from the ends ofthe rollers, through the cut out 24.

In order to protect the rollers from collecting different coloredpowder, I may insert sleeves 36, (FIG. 3) over the ends of the rollers,which sleeves 36 may also be removed endwise through the cut out 24.

ln order to install or remove the endless belt media 25, the coverplates 28, 29, and 30 are firt removed. It will be remembered that theend bearings 19A, 20A, 22A, and 23A are carried by the cover plates 28,29,

replacing the cover plates 28, 29, 30 the bearings 19A,

A, 22A, and 23A carried by them are first placed over the ends of theroller shafts and the cover plates are then secured by the-machinescrews 31.

It is believed that the operationof the device is obvi-.

ous from the foregoing description.

Having described my invention, what I claim and de- 1 me to secure byLetters Patent is:

lates from an electrostatic gun, said front wall length of media havinga rearwardly directed angular portion arranged to travel over aremovable collecting receptacle, means to remove the particulates fromsaid media and deposite them in said receptacle and means to move saidmedia through said front and rear wall areas and return, said rear wallportion of said media being angularly directed with respect to saidfront wall portion, said media being supported for travel over aplurality of elongated rollers and is removable from said rollerslaterally with respect to the length of said media and axially withrespect to said rollers.

2. The structure of claim 1, in which said spray booth is provided withat least one trapezoidal shaped side wall opening, which provides accessto said mediaand said rollers, said opening having removable coversthereon.

3. The structure of claim 2, in which. at least one of said removablecovers supports a bearing having received therein one end of one of saidrollers.

4. The structure of claim 1, in which at least one of said rollers isprovided with a replaceable protective element.

5. The structure of claim 1, including means to move air through bothfront and rear wall areas of said media.

* It I! 4R

1. In a device for trapping and reclaiming dry powder particulates,including a spray booth having an air plenum and an exhaust stack, theimprovement consisting of a continuous length of air permeable media, ofsufficient tensile strength to prevent shear, forming both a flexiblefront wall and a flexible rear wall within said booth, said media beingpositioned ahead of said plenum and stack and arranged to receivepowdered particulates from an electrostatic gun, said front wall lengthof media having a rearwardly directed angular portion arranged to travelover a removable collecting receptacle, means to remove the particulatesfrom said media and deposit them in said receptacle and means to movesaid media through said front and rear wall areas and return, said rearwall portion of said media being angularly directed with respect to saidfront wall portion, said media being supported for travel over aplurality of elongated rollers and is removable from said rollerslaterally with respect to the length of said media and axially withrespect to said rollers.
 2. The structure of claim 1, in which saidspray booth is provided with at least one trapezoidal shaped side wallopening, which provides access to said media and said rollers, saidopening having removable Covers thereon.
 3. The structure of claim 2, inwhich at least one of said removable covers supports a bearing havingreceived therein one end of one of said rollers.
 4. The structure ofclaim 1, in which at least one of said rollers is provided with areplaceable protective element.
 5. The structure of claim 1, includingmeans to move air through both front and rear wall areas of said media.